Molecular Dynamics Investigation of Dislocation Slip in Pure Metals and Alloys

Abstract

Averaged accounting of motion and interaction of dislocations is a natural way to describe plasticity at macroscale in those metals, in which dislocation slip is the main mechanism. This approach describes the inertness of the plasticity development, which is crucial in dynamic problems. On the other hand, such models demand for additional equations and parameters. Molecular dynamics (MD) simulation of elementary processes in the dislocation ensemble at nanoscale is prospective tool for construction of these equations and fitting their parameters. We present MD simulation of the motion of single dislocation lines in pure metals and metals with precipitates. Influence of local stresses on the motion of dislocations in pure metals is discussed. The dislocation motion equation is derived and their parameters are fitted to MD simulations for Al, Cu and Mg. Also we discuss the model for dynamic interaction of dislocation and precipitate intended for description of plasticity in alloys.